2. T34 Tank
The T34 is considered by some to be the best tank of WWII. It started off as a combination of American Christie chassis and German BMW engines in early 1939. When the prototype was finished in 1940 the Soviet Army had accepted it and ordered it into production. The key to the T34 was its rudimentary simplicity. The Tank was cramped, simple in operation, easily repaired, with comparatively thin armor and a high rate of speed (34 mph). One on one the T34 stood little chance against a Panther or Tiger but the Germans often faced 10 to 1 odds. Even with these odds the T34 were destroyed in massive numbers causing the Soviets to upgrade the tank, which primarily consisted of thicker armor and a larger main gun. This upgrade helped but truth be told it was pure numbers that made the T34 successful in battle. In the end, the T34 was produced in larger numbers than any other tank in WWII. The weight of the T34 is 26 tons(76 mm maingun) or 32 tons(85 mm maingun) and was additionally armed with 2 DT 7.62 mm machine guns.
3. 2 1/2 Ton 6X6 CCKW
The 2 1/2 Ton CCKW is affectionately nicknamed the "deuce and a half". The CCKW was dependable on and off road, could carry up to ten thousand pounds of equipment and personnel in the troop carrier/flatbed model. Other variants of the CCKW consisted of the dump truck, water tanker, fuel tanker, air compressor, wrecker, van, platform hoist, bomb transport, fire truck, oil field equipment, drill rig, railroad and chemical decontamination. The infamous "red ball express" used these trucks exclusively in late 1944/early 1945 during the "battle of the bulge". GMC and GMC owned Yellow Truck and Coach Division produced 527,104 of these trucks in between 1941 and 1945. The US Army officiallly phased them out of service in 1956.